Ruby 系列安装 <RVM 版>
RVM安装ruby系统应用免除编译安装的痛苦， 方便快捷。
su
password(...密码)
$ bash < <(curl -s https://rvm.beginrescueend.com/install/rvm)
$ echo '[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load RVM function' >> ~/.bash_profile
$ ln -sf /usr/local/rvm /root/.rvm
$ source .bash_profile
(查看是否安装成功， 命令如下， 看到 rvm is a function 即成功)
$ type rvm | head -1
(check for something to could be installed)
$ rvm list known
(install ruby version of 1.9.2)
$ rvm install 1.9.2
$ rvm use 1.9.2
(ensure installation successful)
$ ruby -v
$ which ruby
(exit the root)
exit
$ sudo rvm use 1.9.2 --default
(more details)
https://rvm.beginrescueend.com/rvm/install/
